Study on glass-forming ability and corrosion performance of Ca-based biomedical materials

Stress shielding and the need for secondary surgery are the two major challenges faced by permanent metallic implants, and the emerging Ca-Mg-Zn calcium-based bulk amorphous alloys, with Young's modulus comparable to that of human bone, good biocompatibility, and in vivo degradation, are highly promising materials for bioimplants. Few studies have been reported on the glass formation ability (GFA) and corrosion degradation behavior of Ca-Mg-Zn amorphous alloys in the human body. In this work, we discuss a study on Ca₅₃₊ Mg₂₀Zn_27- (x = 0, 2, 4, 6, 8, 10) alloys, focusing on changes in Zn content near eutectic points and their impact on microstructure and biological corrosion behavior. A copper mold spray casting method has been developed to prepare amorphous bar alloys and amorphous crystalline composite bar alloys with a diameter of 3 mm, which has been verified by X-ray diffraction, electrochemical treatment, and immersion tests. The experimental results demonstrated that the Ca₃Zn and CaZn₂ phases were precipitated in the 3 mm bar material Ca₅₃₊ Mg₂₀Zn_27- (x = 0, 2, 4), and Ca₅₃₊ Mg₂₀Zn_27- (x = 6, 8, 10) was completely amorphous. The Ca₆₃Mg₂₀Zn₁₇ alloy showed the best glass-forming ability, while the Ca₅₉Mg₂₀Zn₂₁ alloy exhibited superior corrosion resistance. Cytotoxicity experiments showed that Ca-Mg-Zn alloys have good biocompatibility and can be used as biomedical materials.